Valve Clearance Adjustment on 1990 PCM 351W
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Engine Repair
Forum Discription: Engine problems and solutions
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=49148
Printed Date: November-21-2024 at 10:49pm
Topic: Valve Clearance Adjustment on 1990 PCM 351W
Posted By: uncle-buck
Subject: Valve Clearance Adjustment on 1990 PCM 351W
Date Posted: August-29-2020 at 9:17am
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Have been reading the service manual for this engine and am wondering about valve clearance adjustment. The manual refers to a hydraulic lifter compressor tool for bleeding down the lifters. Are they still made and sold? If so, where's the best place to buy one? The manual also lists a spec for "Hydraulic Lifter Collapsed Gap". Is that the correct clearance to be checked and adjusted, if necessary? |
Replies:
Posted By: MrMcD
Date Posted: August-29-2020 at 9:54am
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Your lifters are hydraulic and should never need adjustment . ------------- |
Posted By: uncle-buck
Date Posted: August-29-2020 at 10:09am
| I'm asking about valve stem to rocker arm clearance with the hydraulic lifter completely collapsed. |
Posted By: MrMcD
Date Posted: August-29-2020 at 4:48pm
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That clearance is fully controlled by the lifter if you have hydraulics. Why are you asking? If you have a noisy lifter there are ways to adjust them but you should not need to. Are you setting up a new engine at rebuild? ------------- |
Posted By: uncle-buck
Date Posted: August-29-2020 at 5:00pm
| No. I'm getting ready to replace the exhaust manifolds and want to check the valve train while I'm at it. |
Posted By: SNobsessed
Date Posted: August-29-2020 at 10:37pm
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Don't fix it if not broken
------------- “Beer is proof that God loves us and wants us to be happy.” Ben Franklin |
Posted By: KENO
Date Posted: August-29-2020 at 11:14pm
He's probably asking because of the thread in the link http://www.correctcraftfan.com/forum/forum_posts.asp?TID=49129&title=anyone-recognize-this-sound-from-the-engine" rel="nofollow - link If it's fixed Buck, then you'll be spending a lot of time needlessly doing what you want to do. If it's making noises like before or while running, take it out on the water and run it around at speed, get the oil hot and if you have a stuck lifter(s), it just might unstick itself. It did sit for 6 years after all  |
MrMcD wrote:Posted By: MrMcD
Date Posted: August-31-2020 at 4:49pm
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Ok, after reading post one it makes more sense. Our air in California is pretty dry, I don’t worry at all about oil aging while parked, assuming said engine is properly stored. I normally check the dip stick, if the oil is reasonably clean I fire them up, do all normal checks and then change the hot oil to get out all I can. I’m guessing there are other issues in this engine. ------------- |
Posted By: uncle-buck
Date Posted: August-31-2020 at 7:23pm
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There is one other issue with the engine. New Holley carb installed a couple of weeks ago needs to be tuned. It has a slight hesitation during acceleration. Took the slack out of the accelerator pump linkage and adjusted mixture screws.
Am going to check float levels and install a 6.5 power valve. |
Posted By: SNobsessed
Date Posted: August-31-2020 at 9:24pm
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You might also check your ignition timing & advance.
------------- “Beer is proof that God loves us and wants us to be happy.” Ben Franklin |
Posted By: uncle-buck
Date Posted: August-31-2020 at 10:53pm
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Good idea. Have a Prestolite distributor with a Pertronics electronic ignition conversion kit. Set timing last week at 10 degrees BTDC at idle speed of 700 rpms, but did not check the advance curve. Will do. Thanks. |
Posted By: slmskrs
Date Posted: September-01-2020 at 1:03am
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If anyone is hell-bent on adjusting their hydraulic lifters (like I had to do when I replaced my GT40 heads on my previous GT40), I have a documented procedure (I posted the whole head replacement process previously). The way I did it was completely different than what the manual said, and was based on a F2F discussion with a mechanic that specialized in Ford 351s (I took a lifter when I met with him). Much easier than the process in the manual. But you really have to want to do it before I'll dig up the documentation..... ------------- Gordon '97 Ski Nautique, GT40 |
Posted By: KENO
Date Posted: September-01-2020 at 7:52am
I don't know what your different and I guess, super secret method was, but I think there's a pretty good chance that it's been discussed here on CCF in the past
. |
Posted By: uncle-buck
Date Posted: September-01-2020 at 12:18pm
Rechecked timing and it needed a slight adjustment at idle. I did see some advance when giving it gas, but did not measure it. Installed a 6.5 power valve and adjusted floats to level on the new carb. The float in the primary bowl was way off and the float in the secondary bowl needed a slight adjustment. Will report back after water testing. Thanks |
Posted By: GottaSki
Date Posted: September-01-2020 at 12:26pm
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Caution the floats are a bit offset purposefully due to installation angle. Oh, you likely have the pp transmission.. ------------- "There is nothing, absolutely nothing, half so much worthwhile as messing around with boats...simply messing." River Rat to Mole |
Posted By: uncle-buck
Date Posted: September-01-2020 at 12:35pm
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The boat has the PCM 40A transmission. Thoughts?
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Posted By: KENO
Date Posted: September-01-2020 at 2:45pm
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I'm kinda wondering if you adjusted for best idle with the boat in gear in the water or in neutral . In gear will usually end up with richer idle settings and you'll have less chance of a hesitation on takeoff. You mention the front float being way off but not which way. If it was low, you could have hesitation because of that. Since you have a pretty level mounted engine with the 1.23 transmission your front and rear floats should be good if they're both adjusted so the top of the float is parallel to the top of the bowl when you hold it upside down
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Posted By: uncle-buck
Date Posted: September-01-2020 at 4:07pm
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Ken, I adjusted the idle in neutral, running on the hose in my driveway. They ended up at 1 1/2 turns out. Will reset in gear in the water, either underway or on the trailer. The floats were low, so I agree they may have been the cause of hesitation. They have been adjusted to parallel to the tops of the bowls when held upside down. Thanks
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Posted By: slmskrs
Date Posted: September-02-2020 at 1:05am
LOL When I was doing the head replacements, I looked all over the place on the forum, read up on how people scribed the rods in order to measure them, etc. I tried that, and it sucked, so I talked to the mechanic who told me an easy 'failsafe' way to adjust them. Worked like a charm. I agree it was discussed in the pass on CFF because I posted the whole head replacement and lifter adjustment...  I'm just lazy and don't want to look for the post cuz I don't recall what the thread was called. But I have the procedure on my laptop if anyone wants it. Dang it, now I'm going to have to look for the thread!!!! ------------- Gordon '97 Ski Nautique, GT40 |
Posted By: slmskrs
Date Posted: September-02-2020 at 1:23am
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Found my write up on lifter adjustments. Scroll down to see my long-winded process.... ;) https://www.correctcraftfan.com/forum/forum_posts.asp?TID=25151&KW=lifters&title=pushrods-shimming ------------- Gordon '97 Ski Nautique, GT40 |
Posted By: KENO
Date Posted: September-02-2020 at 7:45am
Well there we go, I knew I could get you to post it
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Posted By: slmskrs
Date Posted: September-02-2020 at 10:23pm
 Ya know, someone pokes you about something, you try to ignore it or put it off, and then it just starts bugging you.... (of course, that was your point...) good job!I'm glad I found it. Didn't realize it was back in 2012 that I replaced the heads on the '96. ------------- Gordon '97 Ski Nautique, GT40 |
Posted By: slmskrs
Date Posted: September-02-2020 at 10:30pm
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BTW, I expected my hydraulic lifter adjustment paste to turn into a hyperlink. Now I see that I gotta use that little icon.... http://www.correctcraftfan.com/forum/forum_posts.asp?TID=25151&KW=lifters&title=pushrods-shimming" rel="nofollow - http://www.correctcraftfan.com/forum/forum_posts.asp?TID=25151&KW=lifters&title=pushrods-shimming I wish the thread I had posted it in had been called something like hydraulic lifter adjustment or something like that. I only found it because I did a search of all posts by me. That's not going to help too many people out, nor does pushrod shimming... ------------- Gordon '97 Ski Nautique, GT40 |